<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<canvas id="canvas" height="500" width="500">
			
		</canvas>
	</body>
	<script type="text/javascript">
		function hu(){
			var context = document.getElementById("canvas").getContext("2d");
			context.strokeRect(0,0,200,200);
			context.arc(100,100,50,0,Math.PI/180*60,true);//圆点x，圆点y，半径，开始角度，结束角度,顺/逆时针画
			context.stroke();
		}
		window.addEventListener("load",hu,true);
		
	</script>
</html>
